1. Field of the Invention
The present invention relates generally to a method of regulating the fuel supply of internal combustion engines, and more particularly, a method for controlling the richness of the air-fuel mixture being suuplied according to motor operating conditions, such as, for example, the barometric pressure, speed and load, in carbureted engines, and an apparatus for carrying out the method disclosed herein.
2. The Prior Art
In such engines, the richness of the air-fuel mixture is usually controlled by the carburetor acting either on its supply or mixing air or its fuel flow.
In the first instance, the supply of air entering the mixing pipe is controlled by a pressure capsule and a vacuum capsule connected to the intake manifold or to the amplified vacuum at the carburetor venturi throat.
In the second case, similar means are used to control a needle valve at the fuel inlet. These methods, which have to control very small and instantaneous changes in flow, unfortunately lack sufficient sensitivity and reliability Thus, the supply of air arriving at vacuum in a mixing pipe through a very narrow orifice, for example, being on the order of 0.7 mm measured with a Solex micrometer, is a quantity extremely delicate to control. Likewise, it is well known that fuel needle valves are precise and delicate devices, which easily get out of adjustment. With these methods, repeatable results are difficult to achieve in mass production. They do not work effectively during deceleration when the mixing system is then ineffectual, and they are practically inapplicable, even under normal running conditions, in more complex systems, such as in the case of two-barrel carburetors.